This invention, in particular, finds application in the field of textile dyeing. A known modern textile dyeing apparatus includes multiple arrays, each comprising a plurality of individual, electronically addressable dye jets. Each of the dye jets in a single array outputs the same color of dye. The arrays are positioned in spaced relation across the path of a moving substrate.
Using such apparatus, the pattern-wise application of dye to the textile materials or substrates requires a large quantity of digitally encoded pattern data which must be sorted and routed to each of the individual dye jets comprising each of the arrays. Each of the arrays of dye jets extends across the width of the substrate path as the substrate moves under the arrays. It has been found advantageous to control individually the time period during which the dye streams produced by the individual dye jets in a given array are allowed to strike the substrate. This allows for shade variations to be produced from side-to-side (and end-to-end) on the substrate by varying the quantity of dye applied to the substrate along the length of a given array.
One such control system capable of providing this capability is described in co-pending U.S. Ser. No. 327,843, entitled "DATA LOADING AND DISTRIBUTING PROCESS AND APPARATUS FOR CONTROL OF A PATTERNING PROCESS", filed on Mar. 23, 1989, now U.S. Pat. No. 4,984,169, the specification of which is hereby incorporated by reference. This system, which is applicable to a variety of marking or patterning systems wherein large quantities of pattern data must be allocated and delivered to a large number of individually controllable imaging locations, processes pattern data received from a real-time processor through the use of specific electronic circuitry which accepts the pattern data in the form of a series of 8-bit units. Each of the 8-bit units uniquely identifies, for each pattern element or pixel, a pattern design element to be associated with that pattern element or pixel.
The term "pattern element" as used herein is intended to be analogous to the term "pixel" as that term is used in the field of electronic imaging. The number of different pattern design elements is equal to the number of district areas of the pattern which may be assigned a separate color.
The term "pattern line" as used herein is intended to describe a continuous line of single pattern elements extending across the substrate, parallel to the patterning arrays. Such pattern lines have a thickness, measured in the direction of substrate travel, equal to the maximum permitted amount of substrate travel under the patterning arrays between array pattern data updates.
In this system, the pattern element data must first be converted to "on/off" firing instructions, (referring to the actuation or deactuation, respectively, of the individual dye streams produced by the dye jets). This is performed by electronically associating the "raw" pattern data with pre-generated firing instruction data from a computer generated look-up table. The raw patterning data is in the form of a sequence of pixel codes. The pixel codes merely define those distinct areas of the pattern which may be assigned a distinguishing color. Each code specifies, for each pattern line, the dye jet response for a given dye jet position on each and every array. In this system the number of arrays equals eight; therefore, each pixel code controls the response of eight separate dye jets (one per array) with respect to a single pattern line.
The raw pattern data for a given array is preferably arranged in sequence, with data for dye jets 1-N for the first pattern line being first in the series, followed by data for dye jets 1-N for the second pattern line, etc. The complete serial stream of such pixel codes is sent to a firing time converter and memory associated with each respective array for conversion of the pixel codes into the respective firing times.
Each firing time converter includes a look-up table having a sufficient number of addresses so that each possible address code forming the serial stream of pattern data may be assigned a unique address in the look-up table. At each address within the look-up table is a byte representing a relative firing time or dye contact time, which, assuming an 8-bit value at the address code of interest, can be zero or one of 255 different discreet time values corresponding to the relative amount of time the dye jet in question is to remain "on". Therefore, each specific dye jet location on each and every array can be assigned one of 256 different firing times.
The firing time data from the look-up table for each array is then further processed to account for the "stagger", e.g., the physical spacing between arrays, and the allocation of the individual firing instructions for each jet in the array. Finally, the individual firing instructions for each jet in the array are sent in parallel to the jet dyeing apparatus for actuation of the individual jets in each array.
These systems require a full line of pattern data to be stored in the real-time processor memory for output to the pattern control system. When it is desired to generate different patterns or repetitions of the same patterns across the width of the substrate, each pattern to be generated must first be converted into a "full machine width" pattern line. For example, the individual corresponding pattern lines of each of three separate patterns must be combined into a single set of composite pattern lines which individually extend across the entire substrate. Because this combining of pattern data into full width pattern lines is a computationally intensive process, it must be done "off-line" from the operation of the dyeing apparatus. Further, the entire pattern must then be written into memory which requires an extremely large memory.
One alternative to formatting the patterns off-line and producing the patterns in an "across the width" format would be to eliminate the "full machine width" conversion process and simply produce each individual pattern, in real-time, down the substrate rather than across. However, it is readily apparent that a tremendous amount of the substrate would then be wasted. For example, a twelve foot wide substrate used to produce a pattern only three feet wide, such as would be suitable for a hall or "runner" carpet, for instance, would waste the remaining nine feet across the substrate width.
There is therefore a need for a process and apparatus which produces multiple patterns or repetitions of the same pattern across the substrate in real-time. Further, the process and apparatus should be capable of producing the pattern beginning at any point along the width of the substrate or be capable of starting the given pattern at any point in the pattern for proper centering of the pattern across the substrate and thus not delivering dye to the edges of the substrate.